Ameliorating effect of melatonin on mercuric chloride-induced neurotoxicity in rats.

Mercury is a highly toxic metal. It induces its toxicity via production of reactive oxygen species. Brain tissues are more susceptible to oxidative damage. Melatonin and its metabolites are free radical scavengers. The aim of this work is to elucidate the neuroprotective effect of melatonin on mercuric chloride-induced neurotoxicity in rats. Fifty male albino rats were used and divided into five groups. Group I acts as normal control. Group II (LD HgCl2) received mercuric chloride at a dose of 2 mg/kg. Group III (HD HgCl2) received HgCl2 at a dose of 4 mg/kg. Rats in group IV (LD HgCl2 +MLT) received HgCl2 2 mg/kg + Melatonin 5 mg/kg. Rats in group V (HD HgCl2+MLT) received HgCl2 4 mg/kg + Melatonin5 mg/kg. This study revealed that mercuric chloride decreased the activity of superoxide dismutase, catalase and glutathione peroxidase enzymes and increased malondialdehyde levels. Toxicity of mercuric chloride lead to upregulation of the gene expression level vascular endothelial growth factor. HgCl2 induced fragmentation of rough endoplasmic reticulum, ballooning of Golgi apparatus, nuclear and cytoplasmic degeneration of pyramidal neurones of rat cerebral cortex. This neuronal damage caused by HgCl2 was significantly improved by melatonin.

PPAR agonists as effective adjuvants for COVID-19 vaccines, by modifying immunogenetics: a review of literature.

BACKGROUND: Several coronavirus vaccine have been fast-tracked to halt the pandemic, the usage of immune adjuvants that can boost immunological memory has come up to the surface. This is particularly of importance in view of the rates of failure of seroconversion and re-infection after COVID-19 infection, which could make the vaccine role and response debatable. Peroxisome proliferator-activated receptors (PPARs) have an established immune-modulatory role, but their effects as adjuvants to vaccination have not been explored to date. It is increasingly recognized that PPAR agonists can upregulate the levels of anti-apoptotic factors such as MCL-1. Such effect can improve the results of vaccination by enhancing the longevity of long-lived plasma cells (LLPCs). The interaction between PPAR agonists and the immune system does not halt here, as T cell memory is also stimulated through enhanced T regulatory cells, antagonizing PD-L1 and switching the metabolism of T cells to fatty acid oxidation, which has a remarkable effect on the persistence of T memory cells. What is even of a more significant value is the effect of PPAR gamma on ensuring a profound secretion of antibodies upon re-exposure to the offending antigen through upregulating lipoxin B4, therefore potentially assisting the vaccine response and deterring re-infection. SHORT CONCLUSION: In view of the above, we suggest the use of PPAR as adjuvants to vaccines in general especially the emerging COVID-19 vaccine due to their role in enhancing immunologic memory through DNA-dependent mechanisms.

Hearing loss among high-risk newborns admitted to a tertiary Neonatal Intensive Care Unit.

PURPOSE: The aim of this work is to identify the most significant risk factors for hearing impairment in high risk neonates hospitalized at our Neonatal Intensive Care Unit (NICU) and to assess the sensitivity of hearing screening tests. METHODS: This study involved 260 neonates admitted to a tertiary NICU; they were classified into two groups; 150 preterm and 110 full terms with risk factors for hearing loss. The hearing screening tests performed were transient evoked otoacoustic emissions (TEOAEs) and the automated auditory brainstem response (AABR). RESULTS: Forty-eight preterm neonates (32%) and 30 full term neonates (27.3%) had pathological AABR. In preterm group, mechanical ventilation more than five days, sepsis, usage of aminoglycosides, loop diuretics, vancomycin alone or in combination with aminoglycosides and prolonged duration of admission were considered risk factors of hearing affection whereas in full term group mechanical ventilation more than five days was the risk factor of hearing affection (p<.05). CONCLUSIONS: The prevalence of hearing loss is highest among high risk neonates and TEOAE and AABR were found to be reliable screening tools. Use of ototoxic drugs and mechanical ventilation for more than five days were significant risk factors for hearing loss in our study population.

Randomized clinical trial of CO2 LASER pinpoint irradiation technique versus chemical reconstruction of skin scars (CROSS) in treating ice pick acne scars.

BACKGROUND: Pinpoint irradiation technique CO2 LASER and Chemical Reconstruction Of Skin Scars (CROSS) are effective treatments for atrophic acne scars as fractional photothermolysis. OBJECTIVE: This study was designed to prospectively compare the use of a pinpoint irradiation technique versus TCA CROSS in treating ice pick acne scars. METHODS: Thirty-two patients with ice pick acne scars were included in this open, label pilot study. Pinpoint irradiation technique by CO2 LASER and TCA CROSS were applied for the study and control group, respectively. Twenty-eight patients with ice pick acne scars were included in this open, label pilot study. They were randomly assigned to two groups: the first group (14 patients) received pinpoint irradiation by CO2 LASER as a study group, and the second group (14 patients) received TCA CROSS as a control group. In both treatments, there were four sessions at 3-week interval, and 3 months of follow up. RESULTS: There were statistically significant difference in acne scar severity index and qualitative scarring grading system in the improvement results between the study and control groups (p < 0.05). CONCLUSION: Pinpoint irradiation technique by CO2 LASER is safe and more effective than TCA CROSS technique. Clinical improvement was achieved in all 14 patients without dramatic adverse effects.